Commercial lawn maintenance is a labor intensive task. Beside the frequent mowing of the lawn to the desired height, proper lawn maintenance additionally includes the steps of applying fertilizer, where the fertilizer is mainly available as solid, granular material, and of spraying liquid weed killers, insecticides and the like over the lawn.
The step of mowing the lawn has been greatly facilitated by the introduction of riding lawn mowers. But there still remain three different lawn care operations to be carried out, i.e., mowing the lawn, applying solid granular fertilizer to the lawn, and spraying liquid weed killers or insecticides over the lawn. Conventionally, these three operations were carried out independently, one after the other, which is not only time consuming, but also requires three different machines. It is expensive to acquire and maintain the machines, burdensome to transport multiple machines, and costly to separately store the machines. Some attempts have been made to combine at least some of these functions in a single machine. However, such combinations mainly have occurred in connection with manually operated walk-behind machines.
In U.S. Pat. No. 3,942,308, granted to Vicendese et al., a walk-behind power-driven lawn mower having a storage bin for dispensing solid granular chemicals from the rear portion thereof is disclosed.
A riding lawn mower having a liquid spray device is disclosed e.g. in U.S. Pat. No. 4,821,959, granted to Browning. However, in this machine the liquid supply tank is elevated even above the seat of the operator, which greatly makes the vehicle less stable and more likely to tip, especially when it is operating on sloped surfaces.
In U.S. Pat. No. 4,352,463, granted to Baker, a lawn treatment spreader machine, having a supply hose attached to a large tank on a truck, for wet and dry materials is disclosed. This machine doesn't include a lawn mower.
Considering the aforementioned three lawn care operations necessary for proper lawn maintenance, none of the prior art devices offers the possibility to carry out these operations in a single step. Nevertheless it would be of great advantage if the lawn care operations involving the mowing, the application of solid granular fertilizer, and the spraying of liquid weed killers or insecticide could be combined in one task, and it would be an additional convenience, if a machine providing these possibilities would be a riding machine. Accordingly, these are the goals which are to be reached by the present invention.